Overflow Box Teeth - Water Level

[Morgandy]

Greg,

I just read your article in RK about overflows, teeth, surface water and such. We have a pre-drilled AGA 210gal, 2 overflows along the back. Our tank water level comes about 1/2 way up the teeth. Lately there has been a lot of surface film that I can't figure out why it won't drain. We are fixing our circulation issues, but, where about should 'ideally' the surface level be along the teeth?

We have a 60gal sump, and a Sequence Barracuda, if you need that info.

thx!

[gregt]

Well, your question is sort of academic as there's not much you can do to adjust it now without ripping the tank apart.

The key to deal with teeth is to keep them clean and clear of obstructions such as algae. Keep them flowing as well as you can.

If the water height is high and can be lowered without reducing water flow, then you may consider breaking a few teeth out to improve flow, but you still need to put grating in or something to prevent fish losses.

There aren't a lot of easy solutions once the tank is up and running with prebuilt overflows...

Personally, if I were really determined to change it, I'd lower the water level a few inches below the overflow and cut all the teeth off and then replace them with a shorter straight piece of acrylic. Easier said than done, especially if the overflows are curved...

[LittleBlueGT]

Could you provide a link to the other two articles about sumps.

[gregt]

Sumps I

Sumps II

Sumps III

[LittleBlueGT]

Thanks!

[Morgandy]

Greg, I'll consider anything at this point!! Our 'glorious' custom engineered star-fire tank with a lot of great features could not come to fruition. Yes, the over-flows are curved, but perhaps something can be figured out. BUT, how do you keep fish from going over that little waterfall that would no longer have teeth?

I'm going to post a pic later today of this film/particle/whatever it is that just won't wash into them for some reason.

thx!

[gregt]

BUT, how do you keep fish from going over that little waterfall that would no longer have teeth?

Read part III. There are pictures and description of how.

The key to getting rid of the scum is making that layer of water that overflows as thin as possible. Again, part III goes into detail on that.

[plack]

I read sumps 1 2 and 3 and never saw the part about the pump size needed I want to know for acroporas in a 150 gallon with coast to coast overflows and (3) 1 1/2 inch drain holes going to a 30 gallon prefilter and a 50 gallon sump what the best return rate gph should be . I guesstimate that for every gallon of tank you should have 5.333 gallons per hour return rate from the sump. That puts it at 800 gph for this size tank. I would appreciate any input and the tank is not even up yet :-)